DESCRIPTION (provided by principal investigator): Inhalants are a serious public health concern. They are among the most common and pernicious forms of substance use and the least studied of the major drugs. Inhalant use is associated with harmful outcomes that rival or exceed those characteristic of other drugs of abuse. They disproportionately affect vulnerable subpopulations including the poor, select minority groups, the mentally ill, and persons involved with the juvenile and criminal justice systems. Inhalants can lead to "sudden sniffing death" and serious accidents. Very little research on inhalant use disorders exists, which is also reflected in minimal description of inhalant use disorders in the DSM-IV. Recent findings have raised questions about the reliability and validity of DSM-IV inhalant use disorders, indicating that further research is needed regarding the dimensionality of problematic inhalant use and key signs and symptoms of inhalant use disorders, including tolerance and withdrawal. This information is necessary to inform the development of clinically useful diagnostic and assessment tools, understand the full range of treatment needs of inhalant users, and to develop evidence-based treatments. The importance is elevated in light of the absence of evidenced-based treatments for inhalant use disorders. The proposed research will help address these gaps in knowledge using data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). NESARC is a nationally representative survey of U.S. residents 18 and older and is among the largest (N= 43,093) and most recently completed psychiatric epidemiological studies. This data source contains DSM-IV concordant data on inhalant-related signs/symptoms and disorders, in addition to Axis I and Axis II psychiatric disorders, for one of the largest community based samples of inhalant users. This study will examine the prevalence, associations, and significance of inhalant symptoms;test the latent structure of DSM-IV inhalant use disorders;and examine diagnostic orphans and alternate symptom configurations of inhalant use disorders. PUBLIC HEALTH RELEVANCE: This study examines the signs and symptoms associated with using inhalants. The purpose of this study is to better understand the course of inhalant use disorders, with a long-term goal of improving assessment and treatment.